This K23 proposal supports Dr. Naomi E. Goldstein's development as an independent researcher with expertise in developing and evaluating mental health-related treatments for adolescent girls in the juvenile justice system. Her long-term goal is to create a comprehensive intervention program for delinquent girls that simultaneously alleviates mental health symptoms, reduces aggression, and prevents recidivism. Girls represent the fastest growing segment of the U.S. justice population. Despite female adolescent detainees'wide range of mental health problems, conduct disorder and other anger-related behavior problems often present the immediate reason young female offenders encounter trouble with the law. In addition, no empirically-based treatments focusing on specific mental health-related problems have been developed or evaluated with this population, including treatments for anger and aggression. Thus, Dr. Goldstein's immediate goal is to develop and evaluate an anger management treatment program for delinquent girls by adapting Lochman, FitzGerald, &Whidby's well-established treatment for younger, non-incarcerated boys. Seventy-two girls in a post-adjudication facility will be randomly assigned to 1) the Anger Management for Girls in the Juvenile Justice System intervention plus standard juvenile justice treatment (AMGJJS) or 2) a standard juvenile justice treatment control condition. It is expected that girls completing AMGJJS will demonstrate lower rates of physical and relational aggression shortly after treatment and lower rates of recidivism and lower anger levels at six-month follow-up. Relationships between physical and relational aggression will be examined, as will the relationships among anger, aggression, and psychiatric diagnoses. During her K-award, Dr. Goldstein will build an advanced knowledge-base in four areas: assessment, research design, treatment, and policy issues. She will accomplish her goals through 1) advanced readings, coursework, seminars, supervised clinical experiences, and collaborative research;2) mentorship by Drs. Thomas Grisso, Kirk Heilbrun, John Lochman, and Ana Nunez;3) consultation with Dr. Jesse Berlin, Dr. Stephen Leff, and Mr. Robert Schwartz;and 4) implementation of the proposed study. Dr. Goldstein's training will be based out of Drexel University, where she is as an assistant professor of psychology.